The kid in each of us is intrigued by the possibility of defying gravity, bouncing along like walking on the moon. The possibility of strapping a miniature trampoline to each foot and bounding across the terrain is fascinating. Accordingly, many attempts have been made to realize such a fantasy. Examples of shoe springs employing metal springs include U.S. Pat. Nos. 1,843,493 to Pfeifenbring and 3,377,722 to Downing. Bouncing shoes that employ pneumatic springs include U.S. Pat. Nos. 1,545,437 to Malone et al., 2,756,517 to Youtz, 4,525,941 to Ruth, Jr., and 4,676,009 to Davis et al.
Among the short comings of each of these devices is the risk to life and limb for the participant. Each of these devices effectively hangs a dead-weight load upon the ankle and most of them produce a torsional moment tending to rotate the toe downwardly about the ankle. This greatly increases the risk of stumbling or misstepping producing ankle injuries and/or falls.
The present invention provides a bouncing boot for recreational exercise which significantly reduces the risk of injury. A shoe platform is equipped with a stabilizer in the form of a clamshell mechanism including a first clamshell member engaging and partially surrounding a front-calf portion of a wearer's leg and a second clamshell member engaging and partially surrounding a rear-calf portion of a wearer's leg. The clamshells are each equipped with shoulder protrusions which engage stops on the pivot mounts of the platform. The two clamshell members can pivot to open positions encompassing an angle of at least 90.degree. for ingress and egress of the wearer's foot but, the engagement of the pivot-limiting shoulders with the stops limit the on-foot tilting of the boot to .+-.15.degree., slightly less than the tilt angle permitted by the ankle. In addition, the stabilizer restricts twisting of the foot about the axis of the leg and longitudinal twisting of the foot about its own axis. The combination of sharing the weight load of the boot with the calf of the leg and limiting twisting about each of three orthogonal axes, significantly reduces the risk of injury to the wearer.
A second important feature which will reduce the risk of injury relates to the center-or-gravity adjustment capability of the present invention. Not all users will be of the same size nor have the same size foot. By providing the boot attachment with means to adjustably accommodate different size feet and providing the pneumatic ball retainer with the capability to assume a plurality of positions, the position of the pneumatic ball spring may be adjusted to best suit the wearer: a position most directly beneath the wearer's center of gravity.
Another unique feature of the present invention has to do with the manner in which the pneumatic ball is secured to the boot. The ball is configured as a first semi-ovoid segment with a first major and minor axis, a second semi-ovoid segment with a second smaller major and minor axis, and a minimum major and minor axis at the intersection of the two segments. This minimum dimension receives an inwardly directed ledge of a receptacle of the ball retainer. The receptacle is secured to the shoe platform using sliding dovetail slots. This sliding capability affords the multiple position adjustability previously referred to. When in use, a force applied to the bottom portion of the first semi-ovoid segment will cause inflating fluid to migrate into the second semi-ovoid segment causing it to expand, further reducing the likelihood of undesired withdrawal of the pneumatic ball from its retainer.
Various other features, advantages and characteristics of the present invention will become apparent after a reading of the following detailed description.